hello
been following this thread for a while.
my 420 has about 25 tanks through it. just completed a MM, compression is 210!!!!
never had a real issue, except when cutting in snow, moisture pulverized the chips into fine dust which collected around worm gear, froze and upon re-starting, stripped out worn gear.
service or dealer support is nice, however, being that i am in a more remote area, i have adjusted to getting all parts, saws,etc through the internet.
Hope things got straightened out, As i would reccomend the 420 as being an above average 40cc saw.
some comment on the weight, however fuel useage is better than a 026, and a stock 026 is not as much fun as the mm420